Covestro Deutschland Ag

Covestro Intellectual Property Gmbh & Co. Kg

Thomas Stetten

Joachim Zechlin

The invention relates to a method for producing isocyanates by phosgenating the corresponding primary amines in the gas phase, wherein the raw gaseous reaction product mixture is cooled and partially condensed by being brought into contact with at least one flow of a quenching liquid, and using a part of the condensed reaction product mixture as a component, optionally the only component, of the at least one flow of the quenching liquid after an additional cooling process. The quenching liquid used in total comprises, based on the total mass, organic solvents in a proportion of maximally 25% by mass, and the remainder of up to 100% by mass consists of at least the isocyanate to be produced. Furthermore, the reaction product mixture components which are not condensed under the influence of the quenching liquid are freed of isocyanate components in a scrubber column, and a scrubber liquid- and isocyanate-containing liquid flow is obtained with, based on the total mass, a content of organic solvents of 0.0% by mass up to 10% by mass, in particular 0.0% by mass up to 5.0% by mass.

Growing community of inventors

Cologne, Germany

Thomas Stetten